SiO2 NANOPARTICLES MODIFICATION WITH POLYMER USING AN ESTERIFICATION METHOD AT ROOM TEMPERATURE
新型室温酯化法接枝聚合物改性SiO2纳米微粒

A novel method for grafting polymer onto the surface of nano-SiO2 particles via the esterification reaction at room temperature,atmosphere,etc.was developed and organic/inorganic composite nano-particles were prepared.The method was carried out via two steps.First,the nano-SiO2 was modified with 3-glycidoxypropyl trimethoxysilane,and then the introduced epoxy groups at the surface of the nano-SiO2 particles were converted into alkyl-hydroxyl groups.Secondly,the polymer was grafted onto the nano-SiO2 surface via the esterification reaction between the alkyl-hydroxyl groups and the carboxyl groups at the polymer terminal at room temperature.The modification of the nano-SiO2 and the resulting composite particles were characterized by XPS,FTIR,TEM and TGA.Results showed that the method has higher grafting efficiency,and the grafted polymer accounted for 55 wt%~70 wt% of the total composite particles.As a result,the particle size increased from 40 nm to 64~75 nm upon the polymer grafting.Consequently,the core-shell composite particles with polymer chains on the outside and SiO2 in the core were obtained.